Role of platelet-derived growth factor in renal injury.

Evidence indicates that PDGF is a major cytokine that impacts on the biology of renal cells and the pathogenesis of renal disease. The biologic effects of PDGF on cells and tissue, whether contraction, proliferation, matrix expansion, or cell migration, can result in beneficial or injurious consequences depending on the particular setting. Although expression of PDGF and PDGF receptors is required for glomerular development, their overexpression can be detrimental in renal disease. The chemotactic and mitogenic effects of PDGF are beneficial in recruitment and repopulation by mesangial cells in focal or diffuse necrotizing diseases. On the other hand, a sustained proliferative response can be detrimental to renal function. There is much to understand about PDGF's role in the cytokine network during renal development and renal injury. Understanding the mechanism of action of PDGF and, specifically, the signaling molecules transduced by the PDGF receptor may lead to the development of new therapeutic strategies to offset the detrimental effect of PDGF. Methods of targeting PDGF to hypocellular or necrotic areas to effect tissue remodeling and repair are a desirable goal (28). On the other hand, promotion of fibroblast proliferation and smooth muscle cell proliferation is a detrimental effect of PDGF that contributes to interstitial and perhaps periglomerular fibrosis as well as atherosclerosis. Ultimately, understanding the role of PDGF and other cytokines in renal development and organogenesis will provide the means to treat glomerular pathology without residual scarring.